Japanese Patent Laid-Open Publication No. Hei. 6-264779 published on Sep. 20, 1994 without examination discloses a known throttle control device that includes a throttle valve for adjusting the amount of air passing through the intake passage of an internal combustion engine and a throttle body in which is accommodated the throttle valve. The throttle body rotatably supports a throttle shaft to which the throttle valve is fixed. A motor is coupled to the throttle valve via a power transmission mechanism for open/close driving of the throttle valve, and a throttle sensor determines the opening amount of the throttle valve. A cover is also secured to the throttle body for accommodating the power transmission mechanism in a space between the cover and the throttle body.
In this known throttle control device, when the acceleration pedal is depressed, the resultant depression amount is determined by a throttle sensor. A signal indicative of the depression amount of the acceleration pedal is issued from the throttle sensor and the motor is driven to rotate the throttle valve through an angle in response to the signal. Thus, the amount of air to be taken into the internal combustion engine is adjusted. Such an adjustment is established with well-known feedback control or PID control (Proportion-Integration-Differential Control) in such manner that the actual opening amount of the throttle valve which is indicated by the signal from the throttle sensor is compared to a target opening amount of the throttle valve which is indicated by the signal of the acceleration sensor for converging the deviation between the two values to zero.
However, with the above-construction, the cover and the throttle sensor are provided separately, thus requiring an independent fixation mounting of each of the cover and the throttle sensor to the throttle body. Thus, the number of parts is increased, with the result that the production cost is increased and the assembly of the device is more complicated.
Accordingly, a need exists for a throttle control device that is not as susceptible to the foregoing disadvantages and drawbacks.
It would thus be desirable to provide a throttle control device possessing a simpler construction and capable of being more easily assembled and with a lower production cost.